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Biomedical subjects

Y Ueda

Publications and source records attributed to Y Ueda.

At least 127 records · Page 7Linked to original sources
PubMed1999

Retrograde cerebral perfusion for aortic arch surgery: analysis of risk factors.

BACKGROUND: Retrograde cerebral perfusion (RCP) has been widely adopted during aortic arch surgery under hypothermic circulatory arrest (HCA). However, the risks in terms of mortality and morbidity in aortic arch surgery using HCA with RCP have not yet been confirmed. METHODS: The present study is a retrospective review of 249 patients who underwent aortic arch surgery at three Japanese cardiovascular centers where RCP is a routine adjunct. The median age was 65 years, and 38 patients were more than 75 years old. The pathology in the aortic arch was atherosclerotic aneurysm in 133 patients and dissection in 116. Seventy patients had surgery on an emergency basis. Surgery was performed through a median sternotomy in 182 patients and through a left thoracotomy in 67. Using HCA with RCP, graft replacement of the total aortic arch was performed in 109, the distal arch in 63, and the ascending aorta and hemi-arch in 66; 11 patients had patch repair. RESULTS: The overall hospital mortality was 25/249 (10%), and 12/70 (17%) in emergent surgery. Stroke developed in 11 patients (4%). The median duration of RCP was 46 minutes (range, 5 to 95). Univariate analysis of risk factors revealed that an age of 75 years or more (p < 0.001), and urgency of surgery (p = 0.02) affected hospital mortality. Multivariate logistic analysis revealed that pump time (p = 0.0001), age (p = 0.0001) and RCP time (p = 0.05) are the most significant risk factors for mortality. The risk factors for mortality and neurological morbidity combined are pump time (p = 0.0001), age (p = 0.0002), and urgency of surgery (p = 0.07); RCP time is marginally significant (p = 0.15). CONCLUSIONS: The dominant risk factors for mortality and morbidity are pump time, urgency of the surgery, and age. RCP is a simple and useful adjunct for aortic arch surgery with up to 80 minutes of HCA, although prolonged RCP is a risk factor for mortality and morbidity.

Adult↗
PubMed1999

Control of breathing in infants born to smoking mothers.

OBJECTIVE: To determine whether infants born to smoking mothers have an abnormal respiratory drive and a blunted ventilatory response to hypoxia. STUDY DESIGN: Sixty-four healthy infants, aged 2 to 24 months, were classified into smoking (n = 19) or non-smoking (n = 45) groups based on maternal smoking habits. Resting ventilation, lung function, and mouth pressure 100 milliseconds after an airway occlusion at the onset of inspiration (P(0.1 )) were measured. The ventilatory response to hypoxia was assessed in 15 infants (6 in the smoking group and 9 in the non-smoking group) while breathing 14% oxygen. RESULTS: Respiratory drive (P(0.1 ) = 4.9 +/- 1.3 cm H(2 )O) was lower in infants in the smoking group compared with those in the non-smoking group (P(0.1 ) = 5.9 +/- 1.2 cm H(2 )O) (P <.05). The time to peak tidal expiratory flow (tPTEF) was also shorter (0.25 +/- 0.04 seconds vs 0.32 +/- 0.09 seconds, P <.05). Infants born to non-smoking mothers showed a significant ventilatory response to hypoxia and a 24.6% increase in P(0.1 ). Infants in the smoking group showed a blunted ventilatory response to hypoxia and no increase in P(0.1 ). A dose-response relationship existed between the number of cigarettes smoked by the mother (0, 1 to 10, >10 per day) and the results for P(0.1 ) and tPTEF. Paternal smoking had no influence on the infant's resting ventilation, respiratory drive, or ventilatory response to hypoxia. CONCLUSIONS: Infants born to smoking mothers have a reduced drive to breathe and a blunted ventilatory response to hypoxia. These findings may contribute to the increased risk of sudden infant death syndrome in these infants.

Analysis of Variance↗
PubMed1999

Silicone prosthesis prevents vertigo due to the defect at the mastoid process after mastoidectomy: a clinical report.

This clinical report describes a 64-year-old woman with a bony defect in the mastoid process after mastoidectomy and who experienced vertigo on cold and windy days during winter. The patient noticed that packing a piece of paper or cotton into the defect prevented the vertigo. The patient refused surgical repair, so a silicone prosthesis was fabricated to fill the defect completely. Electronystagmography confirmed the effectiveness of the prosthesis to prevent nystagmus. Although surgical repair is ideal, prosthesis repair of the defect may prove to be effective in some patients.

Electronystagmography↗
PubMed1999

Distance between mitral anulus and papillary muscles: anatomic study in normal human hearts.

BACKGROUND: Preservation of the annulo-papillary muscle continuity in mitral valve replacement is important. Even in patients who require excision of the mitral apparatus, the continuity can be restored. However, there is no guide to the proper length for the resuspension. METHODS: In 57 normal cadaveric hearts, the distance from the tip of the papillary muscle to its corresponding mitral anulus was directly measured. RESULTS: The distance from the tip of the anterolateral papillary muscle to the left trigone (10-o'clock position: D10) and to the point between the anterior and the middle scallops of the mural leaflet (8-o'clock position: D8) was 23.5 +/- 3.7 mm and 23.2 +/- 3.6 mm, respectively. The distance from the tip of the posteromedial papillary muscle to the right trigone (2-o'clock position: D2) and to the point between the middle and the posterior scallops of the mural leaflet (4-o'clock position: D4) was 23.5 +/- 4.0 mm and 23.5 +/- 3.9 mm, respectively. There was no statistically significant difference among the 4 distances (P =.96). Each distance was significantly longer than the corresponding chordae tendineae (D10 vs the anterior main chorda: 17.2 +/- 3.9 mm, D8 vs the anterior cleft chorda: 14.5 +/- 3.2 mm, D2 vs the posterior main chorda: 17.9 +/- 4.3 mm, and D4 vs the posterior cleft chorda: 14.9 +/- 3.2 mm, respectively; P =.0001). The mean distance had a significant correlation with the mitral annular diameter (r = 0.31, P =.019). CONCLUSIONS: In normal hearts, the annulo-papillary muscle distances of the mitral apparatus are similar in 2-, 4-, 8-, and 10-o'clock positions and correlate with the mitral annular diameter.

Adult↗
PubMed1999

Neurotrophic effect of isoquinoline derivatives in primary cortical culture.

Recent studies indicate that the N-methyl-D-aspartate (NMDA) antagonist, (+)-1-methyl-1-phenyl-1,2,3,4-tetrahydroisoquinoline hydrochloride (FR 115427), enhanced neuronal survival in primary culture of cortical neurons from mouse embryos. In the present study isoquinoline derivatives were examined for the neurotrophic activity in primary culture of cortical neurons and were also examined for anti-NMDA activity. In spite of varying level of anti-NMDA activity, isoquinoline derivatives enhanced neuronal survival at the concentration of 10 microM. To elucidate of the mechanisms of neurotrophic activity in primary cortical culture, nicardipine and flunarizine, known calcium channel blockers, were also tested. Neither nicardipine nor flunarizine showed neurotrophic activity up to the doses causing toxicity in cultured neurons. NBQX, an AMPA receptor antagonist, was also tested for neurotrophic activity. However no enhancement of neuronal survival was observed. These data suggest that one of the mechanisms to promote neuronal survival may depend on the structure of isoquinoline ring. Moreover neurotrophic activity observed in our culture systems might not relate on anti-NMDA activity, blockade of voltage dependent L-type calcium channels and antagonization of AMPA receptor.

Animals↗
PubMed1999

Cavitary lung cancer with an aspergilloma-like shadow.

A 66-year-old man who complained of cough and haemoptysis had a cavitary lesion with the meniscus sign in the right lower lung field on his chest X-ray and CT scan. He had smoked 40 cigarettes daily, for about 46 years. Initially, he was diagnosed with aspergilloma and given an antifungal agent. After 2 months, the cavitary lesion showed a slight irregularity of the inner border. The walls were irregularly thickened and were surrounded by infiltrative densities compared with the previous chest radiograph. Enlargement of right hilar and mediastinal lymph nodes was also observed. The fungus ball-like shadow was fixed on the anterior wall of the cavity and its position was not altered with the patient's movements. These radiographic findings led to suspicion that the lesion might be malignant. Transbronchial lung biopsy of the cavity wall and CT guided needle aspiration biopsy of the fungus ball-like lesion were performed. Microscopic examination revealed a squamous-cell carcinoma in both the cavity wall and the fungus ball-like lesion. There was no evidence of fungal elements. In conclusion, the meniscus sign is most often associated with benign diseases such as aspergilloma, however, one should remember that carcinoma may be a cause.

Aged↗
PubMed1999

Increased intensity of lung infiltrates at the side of lung cancer in patients with lung cancer associated with pulmonary fibrosis.

It has been reported that lung cancer is frequently associated with idiopathic pulmonary fibrosis (IPF). The purpose of this study was to compare the intensity of lung infiltrates between the side associated with lung cancer and the side without lung cancer. Twenty-three patients (24 lung cancers) with primary lung cancer associated with pulmonary fibrosis were retrospectively evaluated. Chest CT findings were evaluated by three expert radiologists using the intensity scores. In 16 of the 23 patients, it was possible to compare the intensity of lung infiltrates between both sides of the lungs. As a result, increased intensity at the side in which lung cancer developed was demonstrated in 12 of 16 patients (75%). In the remaining four patients, intensity of lung infiltrates was the same in both lungs. In operated patients as well as autopsied patients, it was possible to evaluate the pathological findings of lung tissues around cancer cells. This study clearly demonstrates that the intensity of lung infiltrates increased at the side in which lung cancer developed.

Adenocarcinoma↗
PubMed1999

Increase in glutamate-aspartate transporter (GLAST) mRNA during kanamycin-induced cochlear insult in rats.

Kanamycin (KM)-induced changes in expression of the gene for glutamate-aspartate transporter (GLAST) in the rat cochlea were analyzed by Northern blotting. With the administration of KM (600 mg/kg/day) once daily for 20 days, the expression of GLAST mRNA gradually increased and reached a peak on day 20. Although the expression of GLAST mRNA remained at a high level until 12 days after the completion of the KM treatment, it then fell to the normal level within 2 months. Such KM treatment resulted in loss of both inner and outer hair cells and a concomitant profound permanent threshold shift. The present findings suggest that during KM administration, high concentrations of extracellular glutamate released by collapsing hair cells induced GLAST mRNA expression. Increased GLAST mRNA might play an important role in the prevention of the secondary death of spiral ganglion neurons from glutamate neurotoxicity.

ATP-Binding Cassette Transporters↗
PubMed1999

Pravastatin restored the infarct size-limiting effect of ischemic preconditioning blunted by hypercholesterolemia in the rabbit model of myocardial infarction.

OBJECTIVES: We tested to find out whether pravastatin restores the infarct size (IS)-limiting effect of ischemic preconditioning (IP) and if it has any effect on the IP-induced activation of adenosine producing enzyme ecto-5'-nucleotidase which plays a key role in the IP-induced cardioprotection. BACKGROUND: The IS-limiting effect of IP is blunted by hypercholesterolemia. Recently, HMG-CoA reductase inhibitors are shown to have direct cytoprotective effects. METHODS: Rabbits were fed with a normal or cholesterol (1%) added diet with or without pravastatin (5 mg/kg/day) treatment. Infarct size was measured after 30 min occlusion and 3 h reperfusion of circumflex coronary artery with or without the IP procedure (5 min occlusion and 10 min reperfusion). Additionally, ecto-5'-nucleotidase activities of ischemic and nonischemic myocardium were measured immediately after IP procedure. RESULTS: This dose of pravastatin did not normalize the increased level of serum cholesterol. The IS-limiting effect of preceding IP (IS reduced from 36.7% to 9.6%, p < 0.001) was abolished by hypercholesterolemia (from 46.1% to 31.3%, p = NS) and restored by pravastatin treatment (from 35.2% to 9.4%, p < 0.001). Pravastatin treatment did not affect IS or the effect of IP under normocholesterolemia. The activation of ecto-5'-nucleotidase presented as the activity ratio of ischemic to nonischemic myocardium (3.1-fold in normocholesterolemia) was blunted by hypercholesterolemia (1.8-fold, p < 0.05) and restored by pravastatin treatment (2.9-fold). CONCLUSIONS: Pravastatin, at the dose serum cholesterol was not normalized, restored the IS-limiting effect of IP and IP-induced ecto-5'-nucleotidase activation, which were both blunted by hypercholesterolemia. The activation of ecto-5'-nucleotidase may be worth further investigation as a possible mechanism for the hypercholesterolemia-induced retardation and pravastatin-mediated restoration of the cardioprotective effect of IP.

5'-Nucleotidase↗
PubMed1999

EPR imaging for in vivo analysis of the half-life of a nitroxide radical in the hippocampus and cerebral cortex of rats after epileptic seizures.

Recently, we developed an in vivo temporal electron paramagnetic resonance (EPR) imaging technique to be applied to the brain of a rat, into which a blood-brain barrier (BBB)-permeable nitroxide radical, 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM) was injected intraperitoneally. This imaging technique made it possible to measure decay rates of a nitroxide radical in multiple regions of the brain simultaneously. Using this technique, the half-life of PCAM was estimated from the exponential decay of the signal intensity derived from the temporal EPR images in the hippocampus and cerebral cortex of rats after a kainic acid (KA)-induced seizure. The hippocampal half-life of PCAM after KA-induced seizures was significantly prolonged (p < .01), whereas the prolongation of the cortical half-life was not significant. These findings suggest that following a KA-seizure, the intrahippocampal ability to reduce the nitroxide radical is impaired, but the ability is intact in the cerebral cortex. This is the first in vivo quantitative EPR imaging study that has a bearing on the pathogenesis of KA-induced seizures in the brain.

Animals↗
PubMed1999

Different changes in concentrations of monoamines and their metabolites and amino acids in various brain regions by the herbal medicine/Toki-Shakuyaku-San between female and male senescence-accelerated mice (SAMP8).

Due to it's estrogen-secreting qualities, a Japanese herbal medicine, Toki-Shakuyaku-San may have a potential role for Alzheimer's disease in women. The effect of treatment with Toki-Shakuyaku-San testing on concentrations of monoamines, their metabolites and amino acids in the cortex, hippocampus and striatum of senescence accelerated mice (SAMP8) was examined and sex differences of SAMP8 and ddY mice was studied. In the female SAMP8, concentrations of gamma-aminobutyric acid, alanine, and glycine were elevated in three regions after treatment. The concentration of glutamate was decreased in the cortex, hippocampus, and striatum of female and male SAMP8 and not in female and male ddY mice. These results suggest that different effects of Toki-Shakuyaku-San treatment on concentrations of monoamines, their metabolites and amino acids in the brain tissue may be due to its stimulation of secreted estrogen on neurons.

Aging↗
PubMed1999

Functional screening of an asthma QTL in YAC transgenic mice.

Many quantitative trait loci (QTLs) contributing to genetically complex conditions have been discovered, but few causative genes have been identified. This is mainly due to the large size of QTLs and the subtle connection between genotype and quantitative phenotype associated with these conditions. Transgenic mice have been successfully used to analyse well-characterized genes suspected of contributing to quantitative traits. Although this approach is powerful for examining one gene at a time, it can be impractical for surveying the large genomic intervals containing many genes that are typically associated with QTLs. To screen for genes contributing to an asthma QTL mapped to human chromosome 5q3 (refs 6,7), we characterized a panel of large-insert 5q31 transgenics based on studies demonstrating that altering gene dosage frequently affects quantitative phenotypes normally influenced by that gene. This panel of human YAC transgenics, propagating a 1-Mb interval of chromosome 5q31 containing 6 cytokine genes and 17 partially characterized genes, was screened for quantitative changes in several asthma-associated phenotypes. Multiple independent transgenic lines with altered IgE response to antigen treatment shared a 180-kb region containing 5 genes, including those encoding human interleukin 4 (IL4) and interleukin 13 (IL13 ), which induce IgE class switching in B cells. Further analysis of these mice and mice transgenic for mouse Il4 and Il13 demonstrated that moderate changes in Il4 and Il13 expression affect asthma-associated phenotypes in vivo. This functional screen of large-insert transgenics enabled us to identify genes that influence the QTL phenotype in vivo.

Animals↗
PubMed1999

Detection of large molecular weight cytokeratin 8 as carrier protein of CA19-9 in non-small-cell lung cancer cell lines.

It has been reported that cytokeratin 8 (CK8) is expressed in all non-small-cell lung cancers (NSCLC). We hypothesized that antigenic changes of CK8 may occur in some NSCLC cell lines. To prove this, Western immunoblot analysis using anti-human CK8 monoclonal antibodies as well as immunohistological staining of CK8 were performed in NSCLC cell lines. As a result, CK8 which had a higher molecular weight than recombinant CK8 was demonstrated in two of eight NSCLC cell lines. In addition, this CK8 contained antigenic epitopes of CA19-9. This CK8 with higher molecular weight, may have played a role in the process of invasion or metastasis of NSCLC.

Adenocarcinoma↗
PubMed1999

Development of a modified selective amplifier gene for hematopoietic stem cell gene therapy.

We have proposed a novel concept, ie selective expansion of transduced cells, to overcome the low efficiency of gene transfer into hematopoietic stem cells. Previously, a fusion gene encoding a chimeric receptor (DeltaGCRER) between the mouse granulocyte colony-stimulating factor receptor (G-CSFR) and the hormone-binding domain of rat estrogen receptor was constructed as a 'selective amplifier gene'. Although the chimeric gene conferred estrogen-inducible proliferation on the transduced Ba/F3 cells, it also mediated differentiation of the retrovirally transduced 32D cells upon estrogen treatment. Since only a growth signal is required for our purpose, we further modified the DeltaGCRER gene to attenuate its differentiation signal. Based on the observation that tyrosine-703 in wild-type G-CSFR plays a pivotal role in transmitting the differentiation signal, phenylalanine was substituted for this residue in DeltaGCRER. When the resultant selective amplifier gene (DeltaY703F-GCRER gene) was expressed in 32D cells, sustained growth was supported by estrogen, while differentiation was suppressed. These cells ceased to grow upon estrogen withdrawal and differentiated with G-CSF treatment. The present findings suggested that DeltaY703F-GCRER may have desirable properties as a selective amplifier for hematopoietic stem cell expansion and gene therapy.

Animals↗
PubMed1999

Augmentation of local antitumor immunity in the liver by tumor vaccine modified to secrete murine interleukin 12.

Minimal residual lesions have been a major problem in surgical management of cancer. We transfected M5076 with murine IL-12 gene by a retroviral vector, established a stable transfectant secreting IL-12 and investigated its antitumor effects on a spontaneous liver metastasis murine model of M5076 reticulum cell sarcoma. Subcutaneous vaccination of the irradiated transfectant into the remote skin following the amputation of the tumor-bearing limb improved survival when compared with the vaccination of irradiated parental cells (control). Cytotoxic activities against parental M5076 were significantly stronger in the hepatic lymphocytes from the mice vaccinated with the IL-12 transfectant than those from the control. IFN-gamma production of hepatic lymphocytes when they were cocultured with the parental cells was significantly augmented in mice vaccinated with the IL-12 transfectant compared with the control. On the other hand, both cytotoxic activity and IFN-gamma production of spleen cells in the M5076-vaccinated and transfectant-vaccinated mice were at similar levels. Immunophenotypic analysis revealed the selective increase of CD3+NK1+ population in the liver from the transfectant-vaccinated mice. These results suggest that tumor vaccines genetically modified to secrete IL-12 continuously at a relatively low level preferentially augment local antitumor activity in the liver rather than systemic immune responses. This strategy warrants further investigation as an adjuvant modality in the management of postoperative residual tumors.

Animals↗
PubMed1999

Influence of hemodialysis membrane type on pentosidine plasma level, a marker of "carbonyl stress".

UNLABELLED: Influence of hemodialysis membrane type on pentosidine plasma level, a marker of "carbonyl stress." BACKGROUND: The accumulation of advanced glycation end products (AGEs) in uremia has been ascribed to the retention of carbonyl precursors of AGEs. Pentosidine plasma level has been identified as a surrogate marker of carbonyl precursors ("carbonyl stress"). The influence of hemodialysis (HD) membrane type and residual diuresis on carbonyl stress has not been studied. METHODS: We measured protein-linked and free plasma pentosidine (a surrogate marker of carbonyl stress) by high-performance liquid chromatography in patients on HD with low-flux cellulose (N = 29), high-flux polysulfone (PS; N = 57), polymethylmethacrylate (PMMA) (N = 25), and AN69 (N = 15). RESULTS: Both protein-linked and free pentosidine were similar on low-flux cellulose, high-flux PMMA, and AN69, but were lower (P < 0.01) on high-flux PS. Pentosidine levels were virtually identical on Fresenius and Asahi PS in Japanese and Belgian patients. By multivariate analysis, only the type of HD membrane and residual diuresis proved to be independent determinants (P < 0.001) of pentosidine levels. During a single HD session, the clearance of free pentosidine was similar with all membranes. In three patients who were switched from AN69 to PS, the protein-linked pentosidine level dropped to the control level after resumption of the AN69 membrane. CONCLUSIONS: Both HD membrane type and residual diuresis are independent determinants of pentosidine plasma level, which is a marker of carbonyl stress.

Aged↗
PubMed1999

Oral administration of the dopamine prodrug docarpamine shortens need for drip infusion of dopamine in patients with low cardiac output syndrome after cardiac surgery.

BACKGROUND: Docarpamine (DOC) is a dopamine prodrug which can be orally administered. It has been found that oral docarpamine transforms into dopamine in vivo, and increases cardiac output and renal blood flow as effectively as intravenous dopamine. METHODS: We reviewed the records of 26 patients who had developed low cardiac output syndrome (LOS) after cardiac surgery and received docarpamine during the early postoperative course. Five patients discontinued docarpamine within 2 days due to arrhythmia. There were 3 hospital deaths. The remaining 18 patients were divided into two groups according to the timing of docarpamine administration. In group A docarpamine was administered during and after weaning from intravenous catecholamines, in group B only on demand after weaning from intravenous catecholamines. RESULTS: There were 12 patients in group A and 6 in group B, and the severity of LOS was relatively milder in group B than in group A. Stable hemodynamics and sufficient daily urinary output were maintained by oral administration of DOC in both groups just as well as by drip infusion of catecholamines. CONCLUSION: Sinse continuous drip infusion of catecholamine commonly slows recovery in LOS patients, it is considered that switching from drip infusion of catecholamines to oral DOC administration is safe and useful for earlier recovery in LOS patients after cardiac surgery.

Administration, Oral↗